Automatic sectionalizing device.



L. A. HAWKINS. AUTOMATIC SEOTIONALIZING DEVICE. APPLIGATION FILEDSBPTJB, 1911.

1,023,377. Patented Apr. 16, 1912.

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line, which UNITED STATES. PATENT OFFICE.

LAURENCE a. nxwx-ms, o'r unaware COMPANY,

SCHENECTADY, new YO'R'K, ASSIG'NQR 'ro GENERAL A coaroasrron or new70mg.

av'wu'arrc sncnon nmmne xmvzcn tribut'ed along the line, and it isdesired in a short circuit or other failure on case of any part of theline to cut out a sect-ionof the l-lneat the point where-the shortcircuit or failure occurred so that the rest of the line maybe-maintained in operation while the short circuit is being removed, orthe line repaired. Such an arrangement is particularly advantageouswhere there are sources of power at opposite ends of the can feed inopposite directions up to the faulty section, -for in such a case theload may be carried on all the line eX- fThe sectionalizing device ceptthe faulty section.

In the operation of sectionalized transmission lines in the past thesectionalizing switches have been either manually operated, or ifautomatic at all,- ha've operated simply asoverload circuit breakers Ifthe switches are manually operated, which isordinarily the case, thefaulty section can be cnt-outonly by sending a man out onto the line tolocate the short circuit and to pull the sectionalizing switches at bothends Until this is done the entire line between power s ations is=out ofi of the faulty section.

service. Even if overload 'circ'uit breakers are employed forsectionalizing switches it is highly probable that a severe shortcircuit will blow the breakers not onl between the faulty section andthe ad acent section but at a number of other izing points on the line.Consequently a large part of the line is'out of service until a man hasbeen sent'out to locate the trouble and to close theproper switches forener- "zing all sections butthe faulty section.

he advantages of automatic circuit breakers for sectionalizing outfitsare therefore small as compared with manually operated switches and havetherefore been seldom used so far as I am aware. In any case, it

is obvious that with the arrangements here-' employed, a large part ofthe line toforo :Speclflcationiot Letters Batent. Application andSeptember 18, 191 1.

; a sectionalizing ;tirely automatic-in its action.

' short circuit, they K successively and automatically, so as to Be:either direction so that if =section 'betweenfthe two circuited,current may be sectional- Patented Apr. 16, 1912, Serial No. 649,97?

I may be thrown out of service for a consirb a layed over the {portionof the road on which the transmission is interrupted.

The ,object of my invention is to provide device for such transmissionlinesas I have discussed above. which is on+ Upon the occurrenceof-ashort circuit on any part of the line that part is at once disconnectedfrom the power station and if as will hereinafter be explained theswitches at other points open on a serum will at once'close again thefaulty one, is entirely re, versible in its operation, that is, it Worksequally well with current coming from the intermediate stations is shortturned on to the line at either station or both stations, amt allsections between the faulty section and both stations will beautomatically energized, :while the faulty section will be kept out ofservice as long as the-short circuit-is maintained. Thus, there is nointerruption, or at most only a (if-service on 'an energize all sectionsup to section except that which is short circuits My invention will bestbe understood by reference to the accompanying drawing in which-- Figure1 shows diagrammatically a sec tionalized transmission line of the typeto which my invention isapplicable, and Fig. 2 shows diagrammatically anautomatic sec tionalizing device arranged in accordance with myinvention. i

In Fig. 1, A and A represent generators or power stations at opposlteends of a trans mission line. By means 'of switches a and at, eithergenerator may be connected to the line or bothcma-y be'connected theretoso as to operate in parallel. The transmission line is divided intosections B to B at a sectionalitirlg momentary interruption,

, number of points C to C between the power stations. The distributedload oneaoh section is indicated by transformers b to 6 In case of ashort circuit on any section as, for instance, section B it is desirablethat this section should be disconnected from its adjacent sections atpoints C and C but that the connection between sections B and B shouldnot be interrupted, or if momentarily interrupted, should at once herestored, so that generator A may maintain sections B and B in operationwhile gener' ator A maintains section B in operation. At each of thepoints G to C I provide an automatic sectionalizing device such as isshown diagrammatically in Fig. 2. :Sjvitch contacts D are provided forconnecting directly together the sections B and B These contacts areactuated by a magnet winding E which is energized from a stepdowntransformer a connected across the section B. The circuit of winding Eis controlled by a relay F which is energized from the secondary of astep-down transformer f, the primary of which is connected across thesection B These transformers e and 7 may be special transformers forsupplyin these windings only or they may be trans ormerscarrying part ofthe distributed load of the system. 'G represents an impedance connectedin shunt to the switch contacts D and consisting of a double reactivecoil having two windings which may or'may not be on the same magneticcore as indicated and which are connected in shunt to the two contacts-Drespectively. 9, 9 represent fuses in circuit with the windings ofractance G. H and H represent manually operated emergency switches fordisconnecting the apparatus from sections B and B respectively. Jrepresents a synchronizing lamp or other synchronism indicator connectedto the secondary of a transformer j, the primary of which is connectedbetween like wiresof sections B and B Assuming first that the system isin operation with switches H and H closed and contacts D also closed,theltwo sections B and B are then connected directly together. Winding Eis ener ized by the voltage on section B and win in F by the voltage ofsection B and since these two sections are now connected directlytogether, there are now equal voltages on these two windings or at leaston the primaries of the transformers supplying them. If the power iscoming from the left, that is, from section B to section B, and if ashort circuit occurs on section B it will be seen that both sectionswill momentarily lose their voltage and winding E will allow contacts Dto open. This throws the impedance G into circuit between the twosections so that the short circuit on section B is no longer felt onsection B. Consequently if the sectionalizing devices to the left of Bhave not opened, the voltage is immediately restored to this section,the voltage between section B and B being used up in the drop in thereactive windings of impedance G. Voltage is thus restored to theprimary of transformer but winding E cannot close contacts D becauserelay F is deenergized, since there is a short circuit on the primary fwhich supplies this relay. The faulty section is thus cut out while thesection to the left is left in operation. If the short circuit wassudden and severe so as to open the sectionalizing apparatus to the leftof B or even at the power house, such sectionalizing apparatus to theleft of B will close again as soon as the circuit breakers in the powerhouse have been closed, or as soon as the contacts between B and B open,if the circuit breakers at the power house were not tripped. If the loadbetween stations A and A was being carried before the short circuit bystation A alone, then as soon as the short circuit has occurred and thefaulty section B has been disconnected at G, and also at C since themagnet winding E and C was of course without voltage, station A can callup station A and instruct the latter station to close the switches a soasto energize section B The sectionalizing contacts at C will not closefor although relay F at point C is energized, winding E is notenergized, because the primary of the transformer supplying it is shortcircuited. If the short circuit 'oc curred on the section B instead ofsection B then when switches a are closed at station A the contacts D at(I) will close so as to connect B to section B and therefore togenerator A,

if they were open,

but the switch contacts at C will remain open because of the shortcircuit on B. If both stations were operating in parallel at the time ofthe short circuit on any section, as for instance, B, the faulty sectionwill be disconnected at both ends and the remaining sections left inoperation, or if any of these sections were mo mentarily o'pencircuited, the circuit will immediately be restored as soon as theswitch contacts at C and C have opened. Thus, in any case, whether theline is bein fed from one end or the other, or from 0th, the faultysection is cut out at both ends and the remaining sections, ifmomentarily thrown out of service, are immediately restored to servicesimply by closing the circuit breakers or switches a and a at oppositeends of the line.

While the limited current which is passed through'the impedance from onesection to an adjacent short circuiting section is not sufficient tointerfere with the operation of the adjacent sections, it of coursewould be dangerous for a man to work on the short circuited section,because if the short circuit thus throwing the stations into parallel isnot of zero resistance there is still some, voltage between the lines,and also because: as soon as the short circuit is removed fun? voltagewill be restored to the line by the; automatic closing of thesectionalizing de-; vices at the ends of the section. Therefore beforeworkin on the faulty section, as for, instance B the disconnectingswitches H'f should be opened at one end of the, section I and theswitches corresponding to H at the 3 other end of the section. After theline has been repaired or the short circuit removed f the faulty sectionmay be cut into service without interrupting even momentarily the-;'operation of the rest of the line,,if synchronizing means are providedat the sectionalizing apparatus so that the two stations A and A out ofsynchronism. This is the purpose of the synchronizing lamp or otherdevice J. Suppose, for instance, that section B? has been shortcircuited and disconnected at both ends while the sections on each sideof it are kept in operation from the two stations at opposite ends ofthe line. After the short circuit has been removed the disconnectingswitches may be closed at once .at one end of the line, say forinstance, at the right end, whereupon theautomatic devices willimmediately close so that section B will be supplied from generator A.Next, right hand switch H may be closed so as to connect one wire ofsection B with one wire of section B. If the two stations are out' ofsynchronism, this will then be indicated by the lamp or other device Jbut when the, stations have been brought into synchronism by telephonicor other communication, this too will be indicated b the lamp J and atthe pro er instant, which, with the connections s own, will be when thelamp J is dark, the left hand switch H may be closed,

through the reactance G, and this reactance will immediately be shortcircuited by the automatic closing of switch contacts D.

Th'e apparatus above described will take care not only of a direct shortcircuit be' tween the conductors of'a single section but also of a shortcircuit caused by a ground on one wire of one section and a secondground on the other wire of another section. For instance, suppose theupper wire of section B and the lower wire of section B be grounded. Ifall the switches are closed this makes a short circuit on the line.Suppose firstthat the power is coming from generator A. The automaticswitches at C will open, andperhaps also those at C will openmomentarily. The latter switches will however close and a circuit willthen be established from section B through the lower wire of section B,the lower wlndingof reactance G at C to the lower wire of section Bthence through the double ground to the will not be connected when theyare upper wire .of section B and thence to the upper wire of section B.Thusthe full line voltage is thrown on to one winding ofv reactance Ifthis winding is designed to carry the full line voltage, instead of beindesigned for-only the half voltage which it ordinarily carries .upon ashort circuit on a s ngle section, no further result will follow,

and the section B will continue in operation, the load thereon beingshunted by one winding of reactance G at C. If, however, as wouldordinarily be the case, the full voltage on one winding of reactance Gwould cause that winding to draw an excessive current, theonly resultwould be to blow the lower fuse g, as shown in Fig. 2. In either case,section B would be left in operation from A closes the switches a,section B once energized and section B also because of the closing ofthe automatic switches at C The voltage from station A will then bethrown across the other winding of reactance G and either this Windingwill act as a shunt on section B or else the other fuse 9 will blow. Ineither case all the sections are left in operation, with at most amomentary interruption and the blowing of a couple of fuses. The sameresult occurs if the two grounds occur on sections which are notadjacent, as for instance, B and B In this case if the power is comingfrom station A. Then if station will be at station A the automaticswitches at point C willat once close again if they open momen tarily,and this connects sections B and B together so that a ground on one wireof section B then becomes the same as a ground onkthe same wire ofsection B so that the conditions are then precisely the same as thoughthe grounds were on adjacent sec-' tions, which is a condition that hasalready been discussed.

The size'of the impedance G has. been mentioned in connection with thediscussion of double grounds on adjacent sections. Another considerationwhich enters into the proportioning of this impedance is the amount ofload on each section and the voltage required to operate the relay F orthe switch-operating winding E. For instance, during a short circuit onone section, for instance, B, the reactance G its two windin s inseriesa equal to theivo tage on B. no short circuit on B? there iscircuit between the two wires of the section having a certain impedancedepending on the load on that section, so that when section B is innormal condition and the voltage is thrown on to section B the voltagedrop before contacts D close is partly in impedance G and partly in theload on section B The greater the amount of impedance Gthe lower is thevoltage for operating relay F, so that impedance G should must carry inbe designed relative to the load on section B so that under normalconditions an appreciable fraction of the drop'will occur in the devicesconnected across sections B so as to energize relay F. This means thatthe impedance of the device Gr should not be too great, if the automaticdevices are to close properly under normal conditions. On the otherhand, this impedance small for otherwise toolarge a current would bedrawn by the rcactance when there is a short circuit on section B Thebest proportion between the impedance of the devices Gand that of theload'connectedto each adjacent section is determined in each case by theconditions of operation.

I do not desire to limit myself to the particular construction andarrangement of parts shown and described but aim in the appended claimsto cover all modifications which are within the scope of my invention.

/Vhat I claim as new and desire to secure by Letters Patent of theUnited States is 1. In combination, a sectionalized transmission line,switch contacts for connecting adjacent sections directly together,means for passing a limited current from one section to the second whilesaid switch contacts are open, a winding energized from said limitedcurrent in said second section under normal conditions of said secondsection, and means controlled by said magnet winding for closing saidswitch contacts.

2. In combination, a sectionalized transmission line, switch contactsfor connecting adjacent sections directly together, an im pedance inshunt to said switch contacts, and two windings, energized by thevoltages on the two sections respectively, jointly controlling saidswitch contacts.

3. In combination, a sectionalized transmission line, switch contactsfor connecting adjacent sections directly together, an, impedance inshunt to said switch contacts, and

should not be too two windings, energized by the voltages on the twosections respectively, jointly controlling said switch contacts, andmanually operated switches for disconnecting all the above-mentionedapparatus from the line.

4. In combination, a sectionalized trans- I mission line, switchcontacts for connecting adjacent sections directly together, animpedance in shunt to said switch contacts, step-downtransformers havingtheir primaries connected across adjacent sections of the line, twowindings energized from the secondaries of transformers connected toadjacent sections, and means controlled by both windings for controllingthe switch contacts for connecting said adjacent sections together.

5. In combination, a sectionalized transmission line, switch contactsfor connecting adjacent sections directly together, 'an impedance inshunt to said switch contacts, step-down transformers having theirprimaries connected across adjacent sections of the line, an actuatingwinding for said switch contacts energized fromthe secondary of atransformer connected to one section, and a relay controlling thecircuit of said winding energized from a transformer connected to theadjacent sect-ion.

6. In combination, a sectionalized transmission line, switch contactsfor connecting adjacent sections directly together, an impedance inshunt to said switch contacts, an actuating winding for said switchcontacts energized by the voltage on one section, and a relaycontrolling the circuit of said winding energized by the voltage on theadjacent section.

In witness whereof, I have hereunto set my hand this 16th day ofSeptember, 1911. LAURENCE A. HAWKINS.

\Vitnesses:

HELEN Onrono,

Geo. Gr. WHITTLESEY.

